This green chevron 4x32 Trijicon ACOG, or Advanced Combat Optical Gunsight, with 223 Ballistic Reticle, TA51 Mount, and LED RMR 3.25 MOA is a combat riflescope combined with an illuminated reticle for low light situations. Features include a fixed magnification, both eyes open design, superior quality glass, waterproof up to 328 feet, strong aluminum-alloy housing, brightness controls and powered by a single AA battery.